You should just be able to change your CPU ratio from auto to 46 (46x100MHz = 4.6GHz) and then change your CPU voltage to offset mode. After that, it is a matter of upping the offset until you can pass a nice long run through a stress test with no problems. BF3 also seems to find any instabilities as well though this should not replace a standard stress test.

Edit: You also may have to increase the long duration power limit to accommodate this overclock.